How can we detect oil in sea ice?

How can we detect oil in sea ice?

April 4, 2017
Head of Communication

The Norut companies in Narvik and Tromsø don’t meet halfway when they conduct joint experiments, but rather in Hamburg. Using a large tank designed for ship testing, they are combining their expertise in oil behaviour in ice with remote sensing and drone technology. The goal is to map oil spills in sea ice-covered waters.

The three-week Norut-led experiment at the Hamburg Ship Model Basin (HSVA), which started on 15 March, involves around 15 scientists. While spring blooms in the German city, the scientists work shifts of at least four hours in the indoor facility with the temperature set at -15 ˚C. During the experiment, the temperature rises so the ice in the tanks become more porous before eventually melting.

Detecting oil spill in sea ice

The scientists are performing controlled small-scale oil spills in the sea ice. They measure precisely the same ice using two different methods – microanalysis and remote sensing – before comparing the results.

Project Manager Christian Petrich from Norut Narvik, who is coordinating all the work teams, explains:

“The aim of the experiments is to determine the point at which one can register signals from oil in the ice using remote sensing. We hope that this is a step towards finding out when it is possible for a drone to ‘see’ oil that presses up through the ice after an oil spill on or below the surface.”

The various participants in the MOSIDEO project are contributing their respective expertise:

  • Norut Narvik is leading the project and working on ice core measurements, oil analysis and modelling of oil behaviour in the ice.
  • NTNU and University of Alaska Fairbanks are measuring the microstructure in the ice using CT scans of the drill cores, a low resolution mobile scanner and high resolution equipment at NTNU.
  • University of Rennes 1 in France is measuring the ice using tomography, two-dimensional radio waves better known as MR. The radio waves are in the same frequency range as equipment on board satellites.
  • Norut is using remote sensing technology (both optical instruments and radar) to measure the ice in the research laboratory.

Optical and radar instruments

Rolf-Ole Rydeng Jenssen from Norut Tromsø is monitoring eight different remote sensing instruments that are collecting data. Optical instruments as well as radar instruments are mounted on a moveable platform above the tank.

“We are using the instruments to map the oil spills on the surface and under the ice. Among other things, we will acquire more knowledge about how and when we can map the oil before it reaches the surface of the ice,” says Rydeng Jenssen.

“The eight sensors are a mixture of instruments that we have already used in drones and instruments that we are testing with a view to using them in drones in the future. It’s useful to be able to test the equipment and collect data in a controlled experiment,” says Rolf-Ole Rydeng Jenssen. On his return from Germany, he will start a PhD position at Cirfa.

Behaviour of oil in ice

Project Manager Christian Petrich says that HSVA in Hamburg has done an excellent job of arranging for the experiments.

“We have created two types of ice, one formed without wind and the other with wind. So far, we have carried out daily analyses of the ice and corresponding remote measurements. Later, we will discharge a total of 320 litres of crude oil under the ice in preparation for the heart of experiment: To study the behaviour of the oil in the ice on a microscopic scale and compare this with the data from remote sensing.”

Research Scientist Megan O'Sadnick from Norut Narvik also participates in the experiment in Hamburg. The work in Germany forms part of the MOSIDEO project, which is supported by the Research Council of Norway.

Video: See how an oil spill behaves under sea ice - video from the experiment